Herbig Ae/Be accretion rates & mechanisms

We confirm previous findings that the mass accretion rate increases as a function of stellar mass, and the existence of a different slope for lower and higher mass stars, respectively. The mass where the slope changes is determined to be 3.98^+1.37_-0.94M_{sun}_. We discuss this break in the context of different modes of disc accretion for low- and high-mass stars.

Because of their similarities with T Tauri stars, we identify the accretion mechanism for the late-type Herbig stars with the Magnetospheric Accretion. The possibilities for the earlier-type stars are still open, we suggest the Boundary Layer accretion model may be a viable alternative. Finally, we investigated the mass accretion-age relationship.

Even using the superior Gaia based data, it proved hard to select a large enough sub-sample to remove the mass dependence in this relationship. Yet, it would appear that the mass accretion does decline with age as expected from basic theoretical considerations.